The present proposal outlines nine specific projects designed to elucidate significant unanswered questions in the shikimic acid biosynthetic pathway. These include (1), (2), (3) the stereospecific total synthesis of racemic, optically active and isotopically labelled chorismic acid 9; (4) the preparation of close structural analogs of chorismic acid; (5) investigation of the mechanism of chorismate synthetase; (6), (7) the total synthesis of optically active labelled phenylalanine epoxide 44 and cyclo(phenylalanylseryl) epoxide 47 to study gliotoxin biosynthesis; (8) confirmation of the structures of bacilysin 67 and anticapsin 68 by total synthesis; (9) clarification of the biogenesis of bacilysin and anticapsin from the main stem of the shikimate pathway.